An active tactile sensor using fluid for body tissue

This paper presents the development of an active tactile sensor using fluid. Measurement of stiffness and surface conditions, such as sliminess, smoothness, and others, of body tissue is discussed. This sensor is made of a silicone balloon catheter. The balloon is contacted with a soft object and expanded by using fluid. In the process of the expansion, the balloon pushes the object and the contact surface of the balloon slips or sticks. These phenomena depend on stiffness and surface conditions of the object. The expansion can be evaluated by measuring the flow of the fluid. The balloon that is a sensing element is very soft and flexible and does not need electricity. This sensor is available as a medical sensor since it provides safety for human. Experiments using the sensor are carried out on soft samples with various stiffness and surface conditions. It is confirmed that the sensor output are different from each sample. Furthermore, some experiments under different conditions on inner pressure and load are conducted. The results show that the sensor has a potential to measure stiffness and surface conditions.